Big hair, flares, shoulder pads, mini skirts, wide ties, skinny jeans, platform shoes and putting references in powerpoint slides in a tiny font at the bottom of a slide. Just for reference- don’t. No matter who it was suggested to you that leg warmers were back in or that you should use brylcreem fashions come and go and having references on your slides is just another fashion.
The value of the p2 in a presentation is to add value to the whole. It is not the handout. If it is esssentail that the audience take a detailed reference from the presentation make sure this is available in a handout. Even better, supply a link to the document itself.It neither adds kudos to your ascertion, “this is based on the literature” any more than speaking that fact and virtually no one can even read the references let alone effectively copy it down. If they can, then they are not listening to the speaker.
I know everyone does it now, but it used to be everyone was dressed like this.